The failure of current medical practice to effectively treat most victims of cardiac arrest indicates the need for improved therapies. In this report, research studies of external methods of reestablishing blood flow during cardiopulmonary resuscitation (CPR) are reviewed. Emphasis is on mechanisms of CPR and efficacy measurements, with special reference to the effects of newly introduced techniques, including interposed abdominal compression CPR, pneumatic vest CPR, active compression-decompression CPR, and “Lifestick” (Datascope Corp., Fairfield, NJ) CPR. The early promise shown by these new techniques is likely to lead to new options for closed chest CPR.